Wireless sensor device

Abstract

A wireless sensor device capable of constant operation without replacement of batteries. The wireless sensor device is equipped with a rechargeable battery and the battery is recharged wirelessly. Radio waves received at an antenna circuit are converted into electrical energy and stored in the battery. A sensor circuit operates with the electrical energy stored in the battery, and acquires information. Then, a signal containing the information acquired is converted into radio waves at the antenna circuit, whereby the information can be read out wirelessly.

What is claimed is: 
     
       1. A sensor device comprising:
 a substrate comprising an antistatic film; 
 a circuit comprising a plurality of semiconductor elements over the substrate; 
 an antenna electrically connected to the circuit over the substrate; 
 a sensor provided over the substrate and electrically connected to the circuit; and 
 a flexible secondary battery over the substrate and electrically connected to the circuit and the antenna, 
 wherein the sensor device is configured to be implanted in a living body. 
 
     
     
       2. The sensor device according to  claim 1 , wherein the flexible secondary battery is a lithium-ion secondary battery. 
     
     
       3. The sensor device according to  claim 1 , wherein the substrate is a plastic substrate. 
     
     
       4. The sensor device according to  claim 1 , wherein a thickness of the sensor device is less than or equal to 2 mm. 
     
     
       5. The sensor device according to  claim 1 , further comprising a package packing the circuit, the antenna, the sensor and the substrate. 
     
     
       6. The sensor device according to  claim 1 , wherein the sensor is one selected from the group consisting of a photoelectric conversion element, a resistor, an element which uses capacitive coupling, an element which uses induced electromotive force, a photovoltaic element, a thermoelectric conversion element, a transistor, a thermistor, and a diode. 
     
     
       7. A sensor device comprising:
 a substrate comprising an antistatic film; 
 a circuit comprising a plurality of semiconductor elements over the substrate; 
 an antenna electrically connected to the circuit over the substrate; 
 a sensor provided over the substrate and electrically connected to the circuit; and 
 a flexible secondary battery over the substrate, 
 wherein the antenna is configured to receive radio waves and to transmit information wirelessly, 
 wherein the flexible secondary battery is configured to store electrical energy obtained from the radio waves received by the antenna, and 
 wherein the sensor device is configured to be implanted in a living body. 
 
     
     
       8. The sensor device according to  claim 7 ,
 wherein the circuit includes a memory circuit, 
 wherein the memory circuit is configured to store the information acquired by the sensor, and 
 wherein the information wirelessly transmitted by the antenna is the information acquired by the sensor stored in the memory circuit. 
 
     
     
       9. The sensor device according to  claim 7 , wherein the flexible secondary battery is a lithium-ion secondary battery. 
     
     
       10. The sensor device according to  claim 7 , wherein the substrate is a plastic substrate. 
     
     
       11. The sensor device according to  claim 7 , wherein a thickness of the sensor device is less than or equal to 2 mm. 
     
     
       12. The sensor device according to  claim 7 , further comprising a package packing the circuit, the antenna, the sensor and the substrate. 
     
     
       13. The sensor device according to  claim 7 , wherein the sensor is one selected from the group consisting of a photoelectric conversion element, a resistor, an element which uses capacitive coupling, an element which uses induced electromotive force, a photovoltaic element, a thermoelectric conversion element, a transistor, a thermistor, and a diode. 
     
     
       14. A sensor device comprising:
 a substrate comprising an antistatic film; 
 a circuit comprising a plurality of semiconductor elements over the substrate; 
 a first antenna; 
 a second antenna; 
 a sensor provided over the substrate and electrically connected to the circuit; and 
 a flexible secondary battery over the substrate, 
 wherein the first antenna is configured to receive radio waves, 
 wherein the second antenna is configured to receive a signal and to transmit information wirelessly, 
 wherein the flexible secondary battery is configured to store electrical energy obtained from the radio waves received by the first antenna, and 
 wherein the sensor device is configured to be implanted in a living body. 
 
     
     
       15. The sensor device according to  claim 14 ,
 wherein the circuit includes a memory circuit, 
 wherein the memory circuit is configured to store the information acquired by the sensor, and 
 wherein the information wirelessly transmitted by the second antenna is the information acquired by the sensor stored in the memory circuit. 
 
     
     
       16. The sensor device according to  claim 14 , wherein the flexible secondary battery is a lithium-ion secondary battery. 
     
     
       17. The sensor device according to  claim 14 , wherein the substrate is a plastic substrate. 
     
     
       18. The sensor device according to  claim 14 , wherein a thickness of the sensor device is less than or equal to 2 mm. 
     
     
       19. The sensor device according to  claim 14 , further comprising a package packing the circuit, the first antenna, the second antenna, the sensor and the substrate. 
     
     
       20. The sensor device according to  claim 14 , wherein the sensor is one selected from the group consisting of a photoelectric conversion element, a resistor, an element which uses capacitive coupling, an element which uses induced electromotive force, a photovoltaic element, a thermoelectric conversion element, a transistor, a thermistor, and a diode. 
     
     
       21. The sensor device according to  claim 14 ,
 wherein the first antenna is configured to receive the radio waves having a first frequency by utilizing a magnetic field, 
 wherein the second antenna is configured to receive the signal and to transmit the information with use of radio waves having a second frequency by utilizing an electric field, and 
 wherein the first frequency is lower than the second frequency.